Where's the "It Depends" option?
In my experience, B&W is a lot more forgiving than color, so I'm always
much prouder of the color portraits that come out well. I end up converting to B&W when the expression is too good to lose but the exposure or color is off and I just can't figure out how to fix it.
And that's not going into the times where I just feel like B&W expresses the situation better. Some things just work better in black and white, even
with faked grain.